Compressor

ABSTRACT

The present invention relates to a compressor, which has a bolt-cooling part formed between a suction chamber and a bolt fastening hole formed at a position, where the suction chamber and a discharge chamber of a housing are partitioned from each other, for allowing for a flow of refrigerant toward the bolt fastening hole to reduce an influence of temperature of discharged refrigerant, thereby preventing loosening of a bolt due to a thermal expansion, and improving durability.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a compressor, and more particularly, to a compressor, which has a bolt-cooling part formed between a suction chamber and a bolt fastening hole formed at a position, where the suction chamber and a discharge chamber of a housing are partitioned from each other, for allowing for a flow of refrigerant toward the bolt fastening hole to reduce an influence of temperature of discharged refrigerant, thereby preventing loosening of a bolt due to a thermal expansion, and improving durability.

2. Background Art

In general, a compressor for a vehicle inhales refrigerant gas evaporated and discharged from an evaporator, converts it into liquefiable refrigerant gas of a high-temperature and high-pressure state, and discharges the converted refrigerant gas to a condenser.

For such a compressor, there are various kinds, such as a swash plate type compressor in which pistons perform a reciprocating motion by a rotation of an inclined swash plate, a scroll type compressor performing a compression by a rotating motion of two scrolls, a vane rotary type compressor performing a compression by a rotary vane, and so on.

Out of the above kinds of the compressor, as a reciprocating type compressor for compressing refrigerant according to the reciprocating motion of the pistons, there are a crank type compressor and a wobble plate type compressor as well as the swash plate type compressor. In addition, the swash plate type compressor is classified into a fixed capacity swash plate type compressor and a variable capacity swash plate type compressor according to a use purpose.

FIGS. 1 and 2 illustrate a fixed capacity swash plate type compressor according to a prior art. Referring to the drawings, the fixed capacity swash plate type compressor will be described in brief.

As shown in the drawings, the swash plate type compressor 1 includes a front housing 10 having a front cylinder block 20 embedded therein, and a rear housing 10 a coupled with the front housing 10 and having a rear cylinder block 20 a embedded therein.

Here, the front and rear housings 10 and 10 a respectively have discharge chambers 12 and suction chambers 11 formed inside and outside a partition wall 13 in correspondence with a refrigerant discharge hole and a refrigerant suction hole of a valve plate 61, which will be described later.

Here, the discharge chamber 12 includes a first discharge chamber 12 a formed inside the partition wall 13, and a second discharge chamber 12 b formed outside the partition wall 13, partitioned from the suction chamber 11, and fluidically communicated with the first discharge chamber 12 a through a discharge hole 12 c. That is, the second discharge chamber 12 b is partitioned from the suction chamber 11 by partition walls 16 b and 17 formed at both sides of the second discharge chamber 12 b.

Accordingly, the refrigerant of the first discharge chamber 12 a is reduced while passing through the discharge hole 12 c of a small diameter but expanded while moving to the second discharge chamber 12 b. A pulsating pressure drops during the process that the refrigerant is reduced and expanded, so that vibration and noise can be reduced.

Meanwhile, a plurality of bolt fastening holes 16 and 16 a are formed in a circumferential direction of the suction chamber 11. Bolts 80 are inserted and fastened to the bolt fastening holes 16 and 16 a in a state where the front and rear cylinder blocks 20 and 20 a and valve units 60 are assembled between the front housing 10 and the rear housing 10 a.

In addition, the front and rear cylinder blocks 20 and 20 a respectively have a plurality of cylinder bores 21 formed in both directions of a swash plate chamber 24 formed between the front cylinder block 20 and the rear cylinder block 20 a. A plurality of pistons 50 are mounted in the cylinder bores 21 of the front and rear cylinder blocks 20 and 20 a, which are located correspondingly to each other, in such a way as to perform a straight reciprocating motion. In this instance, the pistons 50 are combined to a swash plate 40 by interposing shoes 45 between the pistons 50 and the swash plate 40 inclinedly mounted on a driving shaft 30.

Therefore, the pistons 50 perform the reciprocating motion inside the cylinder bores 21 of the front and rear cylinder blocks 20 and 20 a in cooperation with the swash plate 40 rotating together with the driving shaft 30.

In addition, the valve units 60 are respectively mounted between the front housing 10 and the front cylinder block 20 and between the rear housing 10 a and the rear cylinder block 20 a.

Here, each valve unit 60 includes a valve plate 61 having a refrigerant suction hole and a refrigerant discharge hole, and a suction lead valve 63 and a discharge lead valve 62 mounted at both sides thereof.

As described above, the valve units 60 are respectively assembled between the front housing 10 and the front cylinder block 20 and between the rear housing 10 a and the rear cylinder block 20 a. In this instance, the valve units 60 can be assembled in a position-fixed state since fixing pins 65 formed at both sides of the valve plates 61 are inserted into fixing holes 15 formed on faces of the front and rear housings 10 and 10 a and faces of the front and rear cylinder blocks 20 and 20 a, which are located opposite with each other.

Meanwhile, a plurality of suction passageways (not shown) are formed on the front and rear cylinder blocks 20 and 20 a so that the refrigerant supplied to the swash plate chamber 24 disposed between the front and rear cylinder blocks 20 and 20 a can flow to each suction chamber 11. The second discharge chambers 12 b of the front and rear housings 10 and 10 a are fluidically communicated with each other by a communication passageway 23 perforating through the front and rear cylinder blocks 20 and 20 a.

Therefore, the compressor can simultaneously perform suction and compression actions of the refrigerant inside the cylinder bores 21 of the front and rear cylinder blocks 20 and 20 a according to the reciprocating motion of the pistons 50.

Moreover, the front and rear cylinder blocks 20 and 20 a respectively have support holes 25 formed at the center thereof to support the driving shaft 30, and a needle roller bearing 26 is interposed between the driving shaft 30 and the support hole 25 to rotatably support the driving shaft 30.

Meanwhile, a muffler 70 is mounted on the upper portion of the outer peripheral surface of the rear housing 10 a to supply the refrigerant transmitted from the evaporator to the compressor 1 during a suction stroke of the pistons 50 but discharge the refrigerant compressed in the compressor 1 toward the condenser during a compression stroke of the pistons 50.

A refrigerant circulation process of the compressor 1 having the above structure will be described as follows.

The refrigerant supplied from the evaporator is inhaled to a suction part of the muffler 70, supplied to the swash plate chamber 24 formed between the front cylinder block 20 and the rear cylinder 20 a through the refrigerant suction hole 71, and then, moves to the suction chambers 11 of the front and rear housings 10 and 10 a along the suction passageways formed in the front and rear cylinder blocks 20 and 20 a.

After that, the suction lead valve 63 is opened during the suction stroke of the pistons 50, and in this instance, the refrigerant contained in the suction chamber 11 is inhaled into the cylinder bores 21.

The refrigerant contained in the cylinder bores 21 is compressed during the compression stroke of the pistons 50, and in this instance, when the discharge lead valve 6 is opened, the refrigerant flows to the first discharge chambers 12 a of the front and rear housings 10 and 10 a, passes through the second discharge chambers 12 b, and finally is discharged to a discharge part of the muffler 70 through the refrigerant discharge hole 72 of the muffler 72. After that, the refrigerant discharged to the muffler 70 flows to the condenser.

Meanwhile, the refrigerant compressed in the cylinder bores 21 of the front cylinder block 20 is discharged to the first discharge chamber 12 a of the front housing 10, moves to the second discharge chamber 12 b, and then, moves to the second discharge chamber 12 b of the rear housing 10 a along the communication passageway 23 formed in the front and rear cylinder blocks 20 and 20 a. The refrigerant flowing to the second discharge chamber 12 b is mixed with the refrigerant contained in the second discharge chamber 12 b, and then, discharged to the discharge part of the muffler 70 through the refrigerant discharge hole 72.

Meanwhile, one of the plural bolt fastening holes 16 and 16 a formed in the circumferential direction of the suction chamber is formed at a partition wall 16 b where the second discharge chamber 12 b is partitioned from the suction chamber 11.

However, during the compression stroke of the pistons 50, the high-temperature and high-pressure refrigerant discharged from the cylinder bores 21 to the first discharge chamber 12 a is discharged to the muffler 70 after passing through the second discharge chamber 12 b. In the above process, the high temperature of the refrigerant passing through the second discharge chamber 12 b is transferred to the bolt fastening hole 16 a through the partition wall 16 b, which is in contact with the second discharge chamber 12 b.

That is, since the bolt fastening hole 16 a is thermally expanded due to an influence of temperature of the discharged refrigerant, the bolt 80 coupled with the bolt fastening hole 16 a gets loose and the refrigerant existing in an area of the bolt fastening hole 16 a is leaked.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior arts, and it is an object of the present invention to provide a compressor, which has a bolt-cooling part formed between a suction chamber and a bolt fastening hole formed at a position, where the suction chamber and a discharge chamber are partitioned from each other, for allowing for a flow of refrigerant toward the bolt fastening hole to reduce an influence of temperature of discharged refrigerant, thereby preventing loosening of a bolt due to a thermal expansion, preventing leakage of the refrigerant, and improving durability.

To accomplish the above object, according to the present invention, there is provided a compressor comprising: front and rear housings, each housing having a plurality of bolt fastening holes formed in a circumferential direction therein, a suction chamber and a discharge chamber partitioned from each other by partition walls formed therebetween, and a bolt-cooling part formed between the suction chamber and the bolt fastening hole formed at the partition wall where the suction chamber and the discharge chamber are partitioned from each other to allow for a flow of refrigerant toward the bolt fastening hole; front and rear cylinder blocks mounted between the front housing and the rear housing; and a plurality of pistons mounted inside cylinder bores of the front and rear cylinder blocks for performing a reciprocating motion in cooperation with a rotating motion of a swash plate rotating in a swash plate chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:

FIG. 1 is a sectional view of a compressor according to a prior art;

FIG. 2 is a sectional view taken along the line of A-A of FIG. 1;

FIG. 3 is a sectional view of a compressor according to the present invention; and

FIG. 4 is a sectional view taken along the line of B-B of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will be now made in detail to the preferred embodiment of the present invention with reference to the attached drawings.

In the present invention, description of the same parts and operations as the prior art will be omitted.

FIG. 3 is a sectional view of a compressor according to the present invention, and FIG. 4 is a sectional view taken along the line of B-B of FIG. 3.

First, the compressor 1 according to the present invention includes: front and rear housings 10 and 10 a respectively having discharge chambers 12 and suction chambers 11 formed therein, the discharge chamber 12 being partitioned from the suction chamber 11 by a partition wall 13 formed therebetween; front and rear cylinder blocks 20 and 20 a mounted between the front housing 10 and the rear housing 10 a and having a plurality of cylinder bores 21 formed in both directions of a swash plate chamber 24 formed between the front cylinder block 20 and the rear cylinder block 20 a; a driving shaft 30 rotatably supported on the front and rear cylinder blocks 20 and 20 a; a swash plate 40 rotating together with the driving shaft 30; and a plurality of pistons 50 combined to the outer periphery of the swash plate 40 by interposing shoes 45 between the swash plate 40 and the pistons 50 and performing a reciprocating motion inside the cylinder bores 21.

Here, each of the discharge chambers 12 of the front and rear housings 10 and 10 a includes: a first discharge chamber 12 a formed inside a partition wall 13; and a second discharge chamber 12 b formed outside the partition wall 13, partitioned from the suction chamber 11, and fluidically communicated with the first discharge chamber 12 a through a discharge hole 12 c. That is, the second discharge chamber 12 b is partitioned from the suction chamber 11 by partition walls 16 b and 17 formed at both sides of the second discharge chamber 12 b.

Accordingly, refrigerant of the first discharge chamber 12 a is reduced while passing through the discharge hole 12 c of a small diameter but expanded while moving to the second discharge chamber 12 b, and so, a pulsating pressure drops during the process that the refrigerant is reduced and expanded, whereby vibration and noise can be reduced.

Meanwhile, a plurality of bolt fastening holes 16 and 16 a are formed in a circumferential direction of the suction chambers 11 of the front and rear housings 10 and 10 a. So, the front and rear housings 10 and 10 a can be coupled and fixed with each other by fastening bolts 80 into the bolt fastening holes 16 and 16 a in a state where the front and rear cylinder blocks 20 and 20 a and valve units 60 are assembled between the front and rear housings 10 and 10 a.

Moreover, the front and rear cylinder blocks 20 and 20 a respectively have a plurality of suction passageways (not shown) formed in such a way that inhaled refrigerant supplied to the swash plate chamber 24 disposed between the front cylinder block 20 and the rear cylinder block 20 a flows to each suction chamber 11. The second discharge chambers 12 b of the front and rear housings 10 and 10 a are fluidically communicated with each other via the communication passageway 23 perforating through the front and rear cylinder blocks 20 and 20 a.

Furthermore, the valve units 60 are respectively assembled between the front housing 10 and the front cylinder block 20 and between the rear housing 10 a and the rear cylinder block 20 a. Each valve unit 60 includes a suction lead valve 63, a valve plate 61 having a refrigerant suction hole and a refrigerant discharge hole, and a discharge lead valve 62, which are formed in order from a direction of the front and rear cylinder blocks 20 and 20 a.

Here, the valve units 60 are combined and fixed to the front and rear housings 10 and 10 a and the front and rear cylinder blocks 20 and 20 a in such a way that fixing pins 65 formed at both sides of the valve units 60 are inserted into fixing holes 15 formed on faces of the front and rear housings 10 and 10 a and faces of the front and rear cylinder blocks 20 and 20 a, which are located opposite with each other.

In addition, the front and rear cylinder blocks 20 and 20 a respectively have support holes 25 formed at the center thereof for supporting the driving shaft 30, and needle roller bearings 26 are respectively mounted in the support holes 25 to rotatably support the driving shaft 30.

Meanwhile, a muffler 70 is mounted on the upper portion of the outer peripheral surface of the rear housing 10 a to supply the refrigerant transferred from an evaporator to the compressor 1 through a refrigerant suction hole 71 during a suction stroke of the pistons 50 and to discharge the refrigerant compressed in the compressor 1 toward a condenser through a refrigerant discharge hole 72 during a compression stroke of the pistons 50.

Such a compressor 1 is operated by selectively receiving driving power of an engine by a restriction action of an electronic clutch (not shown).

In the compressor 1, one of the plural bolt fastening holes 16 and 16 a formed on the circumference of the suction chamber 11 is formed at a partition wall 16 b where the second discharge chamber 12 b is partitioned from the suction chamber 11.

In the present invention, a bolt-cooling part 100 is formed between the suction chamber 11 and the bolt fastening hole 16 a, which is formed at the partition wall 16 b where the second discharge chamber 12 b is partitioned from the suction chamber 11, to allow for a flow of the refrigerant toward the bolt fastening hole 16 a.

That is, the bolt-cooling part 100 allows that some of the inhaled refrigerant flows toward the bolt fastening hole 16 a, so that the bolt fastening hole 16 a is cooled by the inhaled refrigerant to thereby prevent an influence of temperature of the discharged refrigerant and loosening of the bolt 80 by a thermal expansion.

The bolt-cooling part 100 is constructed by tieredly forming a communication passageway 101 on the partition wall 16 b on which the bolt fastening hole 16 a is formed to fluidically communicate the suction chamber 11 and the bolt fastening hole 16 a with each other, and so, the bolt fastening hole 16 a can be communicated with the suction chamber 11 and the swash plate chamber 24. So, the inhaled refrigerant introduced into the swash plate chamber 24 flows toward the bolt fastening hole 16 a, and the inhaled refrigerant flowing to the bolt fastening hole 16 a moves to the suction chamber 11 through the communication passageway 101.

Therefore, besides the channel where the refrigerant inhaled into the swash plate chamber 24 flows to the suction chamber 11 through the suction passageways (not shown) of the front and rear cylinder blocks 20 and 20 a, the compressor 1 according to the present invention has additional refrigerant flow channel (C) where the refrigerant flows to the suction chamber 11 through the bolt fastening hole 16 a. As described above, during the process that the inhaled refrigerant of the swash plate chamber 24 flows to the suction chamber 11 through the bolt fastening hole 16 a, oil mixed with the refrigerant is also supplied to the bolt fastening hole 16 a to cool the bolt fastening hole 16 a, whereby the thermal expansion by the discharged refrigerant can be prevented.

That is, the front and rear cylinder blocks 20 and 20 a and the valve units 60 respectively have through holes 22 to which the bolts 80 are inserted and fastened to couple and fix the front and rear housings 10 and 10 a with each other via the bolts 80. So, the refrigerant inhaled to the swash plate chamber 24 can flow to the bolt fastening hole 16 a through the through holes 22, and the inhaled refrigerant flowing to the bolt fastening hole 16 a moves to the suction hole 11 through the communication passageway 101.

In addition, since the refrigerant contained in the suction chamber 11 is always in contact with the bolt fastening hole 16 a by the communication passageway 101, a cooling effect of the bolt fastening hole 16 a can be improved more.

Meanwhile, the communication passageway 101 serves to flow the inhaled refrigerant of the swash plate chamber 24 to the suction chamber 11 through the bolt fastening hole 16 and to circulate the refrigerant of the suction chamber 11 toward the bolt fastening hole 16 a. That is, since the communication passageway 101 is formed in an “U” shape fluidically communicating with the bolt fastening hole 16 a, the refrigerant of the suction chamber 11 and oil mixed with the refrigerant can be circulated while passing through the bolt fastening hole 16 a through the communication passageway 101, whereby the cooling effect is maximized.

Additionally, besides the refrigerant flow channel (C) described above, some of the refrigerant contained in the suction chamber 11 can flow toward the bolt fastening hole 16 a and move to the swash plate chamber 24 through the communication passageway 101 by the rotating motion of the swash plate 40 in the swash plate chamber 24. Of course, also during the above process, a good cooling effect can be obtained while the refrigerant passes through the bolt fastening hole 16 a.

As described above, according to the compressor 1 of the present invention, the bolt-cooling part 100 is formed between the suction chamber 11 and the bolt fastening hole 16 a, which is located at the partition wall 16 b where the discharge chamber 12 is partitioned from the suction chamber 11, out of the plural bolt fastening holes 16 and 16 a formed in the circumferential direction of the suction chambers 11 of the front and rear housings 10 and 10 a, so that the inhaled refrigerant flows toward the bolt fastening hole 16 a to cool the bolt fastening hole 16 a.

So, during the compression stroke of the pistons 50, the high-pressure and high-temperature refrigerant discharged from the cylinder bores 21 moves to the first discharge chambers 12 a of the front and rear housings 10 and 10 a, moves to the second discharge chambers 12 b through the discharge hole 12 c, and then, moves to the condenser through the refrigerant discharge hole 72 of the muffler 70.

Here, the discharged refrigerant passing through the second discharge chamber 12 b is the high-pressure and high-temperature refrigerant, and the high temperature of the refrigerant is transferred to components adjacent to the refrigerant. In this instance, even though the high temperature of the discharged refrigerant is transferred toward the bolt fastening hole 16 a which is in contact with the second discharge chamber 12 b, the bolt fastening hole 16 a is cooled by the bolt-cooling part 100 to thereby prevent the thermal expansion and loosening of the bolt 80.

The present invention is described in connection with an example that the structure having the bolt-cooling part 100 to allow the flow of the inhaled refrigerant toward the bolt fastening hole 16 a, which is in contact with the second discharge chamber 12 b, is applied to the fixed capacity swash plate type compressor 1, but is not restricted to the above, and can be applied to compressors of various kinds, such as a variable capacity swash plate type compressor, a motor driven compressor and others, in the same method and structure as the above to obtain the same effects.

As described above, according to the present invention, the compressor can prevent loosening of the bolt due to the thermal expansion, prevent a leakage of the refrigerant, and improve durability, since the bolt-cooling part is formed between the suction chamber and the bolt fastening hole formed at a position, where the suction chamber and the discharge chamber are partitioned from each other, for allowing for a flow of refrigerant toward the bolt fastening hole to reduce an influence of temperature of discharged refrigerant.

While the present invention has been described with reference to the particular illustrative embodiment, it is not to be restricted by the embodiment but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiment without departing from the scope and spirit of the present invention. 

1. A compressor comprising: front and rear housings, each housing having a plurality of bolt fastening holes formed in a circumferential direction therein, a suction chamber and a discharge chamber partitioned from each other by partition walls formed therebetween, and a bolt-cooling part formed between the suction chamber and the bolt fastening hole formed at the partition wall where the suction chamber and the discharge chamber are partitioned from each other to allow for a flow of refrigerant toward the bolt fastening hole; front and rear cylinder blocks mounted between the front housing and the rear housing; and a plurality of pistons mounted inside cylinder bores of the front and rear cylinder blocks for performing a reciprocating motion in cooperation with a rotating motion of a swash plate rotating in a swash plate chamber.
 2. The compressor according to claim 1, wherein the bolt-cooling part is a communication passageway formed on the partition wall on which the bolt fastening hole is formed for fluidically communicating the suction chamber and the bolt fastening hole with each other. 